Background: Tipaimukh sub-division is one of the thirty one tribal development blocks of the state of Manipur, India. The population of the block is, according to the 1991 census, is 23,993. It lies on the extreme south bordering the state of Mizoram. The term Tipaimukh means the meeting point or confluence of the two rivers- Tuivai aand Tuiruong(Barak). The people living in and around Tipaimukh are Hmars of Mizo ethnic group. To them, Tipaimukh is known as Ruonglevaisuo. It is here that the Tipaimukh hydro-electric project envisages construction a 390 m. long, 162.8 m high earthen core rock-fill which is one of the biggest dams in India. Therefore, the environmental and ecological issues arising out of this project merit immediate attention and action.

Originating from the northern flank of the 1784 m. high peak situated at the east of Senapati district (north), Barak river has a long and winding course running towards south, southwest and suddenly taking a U-turn towards north just at the dam site. Several perennial streams drain into Barak River upstream of Tipaimukh.

Environmental and ecological issues:

A project of this magnitude cannot but have tremendous environmental and ecological impact on the life of the indigenous people living there and on their lands. As it has been mentioned earlier, the lower tract of the catchment above Tipaimukh is inhabited mainly by Hmars and upper part by Kukis with a section of Nagas. Because of the inaccessibility of the tract, plentiful forest land, development of land resources on scientific lines was sluggish leading to continued poverty.

2:1 The watershed: The total catchment area of the river Barak in so far as Manipur and Mizoram are concerned is 9567 sq.km (Manipur) and 9866 sq.km. (Mizoram). The entire catchment area has been covered by soil survey. However, soil formation in composite tracts do not vary with variations of administrative boundaries. 75% of the catchment area having been studied is considered enough of a guide for the entire catchment. The national Bureau of Soil Survey and Land use Planning, Government of India, carried out soil survey in Manipur part of the catchment area and recognized 14 series.

2:2 Forest: The geographic area of the state is 22,327 sq.km of which 15,154 sq.km is recorded as forest. The actual forest cover of the state is 17,418 sq.km which constitutes 78% of the geographic area. According to the State Forest Report of 1997, there is a decrease of 140 sq.km in the forest cover in the present assessment. The dense forest decreases by 381 sq.km. This decrease in forest cover is mainly due to shifting cultivation amounting to 603 sq.km. Present survey report shows that of the overall change of 747 sq.km in dense forest area, 693 sq.km changes to open forest and 54 sq.km of forest. Between 1995 and 1997 assessments, 603 sq.km of forest area is lost to shifting cultivation.

2:3 Shifting cultivation: Shifting cultivation is one of the major causes of decrease in the forest cover not only in Manipur but also in different states of Northest India. This shifting cultivation is actually the slash and burn system of cultivation. An area is taken up, vegetation cut and burnt, one crop of paddy raised and then this area abandoned and another piece of land taken up for similar treatment. The Jhuming cycle used to be 10 to 15 years earlier but due to increase in population, the cycle has come down to 3 to 5 years. In Manipur, 95% of household under Jhum. 50.000 households in the catchment area are estimated to practise shifting cultivation. In Mizoram side, one family covers one hactre under jhuming annually and 11,000 families are assumed to be engaged in shifting cultivation.

The practice of shifting cultivation keeps the people barely at subsistence level. Population sustaining and supporting capacity of land under shifting cultivation has been found to be as low as 3 to 16 sq.km in Manipur and Mizoram. The system does not help in producing surplus for reinvestment.

Practically whole of the area has been affected by this practice of jhuming resulting in clearance of tree over and degradation of land. Only very few pockets of forest are left now which can be said to have original vegetation and eco-system. Another serious impact of jhuming cultivation is on wildlife habitat. Jhuming not only destroys the wildlife habitat but also kills all forms of wildlife in a bid to save their crops one the one hand and to supplement the diet with non-vegetarian food on the other. As the jhuming areas are scattered all over the forest, these kills go unpoliced.

2:4 Soil erosion: There has not been so far scientific management of the forest in these hill regions. The successive local administrations, rather than controlling/regulating transit of forest produce checking any illicit feeling and export, used control and issue of transit passes on payment for collecting revenues. This results in unscrupulous forest contractors resorting to large scale felling and more so of various species. These over-feelings has been continuing for hundreds years resulting in depletion of forest trees and bamboos. As has been pointed out, by far the most destructive and erosive agent is the shifting cultivation. Thus, the average annual soil loss rate is as given below;

Landuse Area in the catchment ha. Annual soil loss t/ha Total annual soil loss from the catchment (tones)

Wet Rice cultivation 6,610 2.80 18,500

Shifting cultivation 70,130 40.05 28,71,824

Forests 7,28,905 0.52 3,79,030

Mixed Forest/bamboos 4,70,155 18.95 89,09,437

Total 12,75,800 62,32 121,78,799 Or say 122 lakh tones.

It is thus clear that unless development measures associated with a forestation and improved agricultural practices are being resorted to in the catchments area of the Tipaimukh dam, the dormant economic condition of the people is bound to deteriorate further.